When I was younger I figured I didn't need to wear a PFD because I was a surf life saver and could swim like criminey.

However, there are a number of scenarios that we don't like to think about that could have you in the water in a debilitated state and unable to support yourself without the assistance of the PFD.

Worst case scenario is that a PFD is going to enable your body to be retrieved without the customary (depending on the water temparatures) two week waiting time before it floats back up ... some bodies just never come back.

Slightly better reason is that your debilitated body won't sink from sight and your buddies can retrieve you and attempt resucitation with minimal delay.

Scenarios in no particular order when a PFD would be handy:
Head injury
Heart attack
Stroke
Capsize and dislocated shoulder
Vertigo/fainting
Fatigue
etc etc etc

Besides a half decent PFD is a handy place to have your hydration system, food and safety gear so that that stuff is always with you and accessible.

So my suggestion is ALWAYS wear a PFD and set an example to the yound surf life savers irrespective of your skills, conditions or locations.

Take care

Pete